Download invasive plants of ohio - Ohio Invasive Plants Council

INVASIVE PLANTS OF OHIO
Fact Sheet 2
Common & Glossy Buckthorns
Rhamnus cathartica, Frangula alnus
GLOSSY BUCKTHORN
DESCRIPTION:
Glossy and common buckthorns are
woody shrubs or small trees that can
attain a height of 20 feet. The cut stems
reveal a distinctive yellow sapwood and
pink to orange heartwood.
Glossy buckthorn has gray-brown bark
and lightly-colored lenticels giving the
bark a speckled appearance. Leaves
are 1-3 inches long, shiny dark green
above, oval-shaped and slightly wavy.
The creamy-green flowers are 5petaled. Plants flower from May to June. The purple-black fruits ripen from July to
September. The fernleaf buckthorn variety ‘Asplenifolia’ has been discovered in bogs
and other peatlands in northeastern Ohio.
Another form, tallhedge buckthorn
‘Columnarus,‘ is a rare, local escape.
Common buckthorn has slender, glabrous stems
often tipped with a spine. Leaves are 1 to 2½
inches long, oval, rounded or pointed at the tip and
have jagged, toothed margins. The upper and
lower leaf surfaces are without hairs. Leaves
appear dark, glossy green on the upper surface
and stay green late into fall. This dioecious shrub
has small, 4-petaled yellowish-green flowers. Its
dark purple-black fruits ripen July to September.
GLOSSY BUCKTHORN
These buckthorns were introduced to North
America from Eurasia as ornamental shrubs for
fence rows and wildlife habitat.
Introduction of
buckthorn was based on its hardiness and ability to thrive in a variety of soil and light
conditions. Both species are well-established in central and northern Ohio. These
species may be confused with Ohio’s native buckthorns, alder-leaved (Rhamnus
alnifolia), lance-leaved (R. lanceolata), and Carolina buckthorns (R.caroliniana), which
are uncommon or rare in the state.
HABITAT:
Glossy buckthorn invades wetlands, which includes swamps, bogs, fens and wet
meadows. It also occurs in upland habitats such as open woods, woodland edges, old
fields and roadsides. Common buckthorn is primarily an invader of uplands, such as
open woods, woodland edges, prairies, and open fields. It also invades flat woods, fens,
and other moist to wet habitats, but less frequently than glossy buckthorn.
COMMON BUCKTHORN
INVASIVE CHARACTERISTICS:
Glossy and common buckthorns tend to form dense,
even-aged thickets (of seedlings, saplings, or
sprouts), crowding and shading out native shrubs
and herbs, often completely displacing them.
CONTROL:
Mechanical: Hand-pulling can be effective for small
populations. The entire plant, including the roots,
should be removed or re-sprouting may occur. For
thickets of seedlings or small saplings, repeated
mowing or bush-hogging may be effective, but
vigorous re-sprouting will occur. Cutting or mowing invigorates both buckthorn species
to resprout, often creating a larger problem, particularly in wetlands, so mechanical
methods are generally ineffective. Prescribed burning may be used, but fire only topkills the stems and must be repeated on a 3-5 year frequency to reduce sprouting. Most
glossy buckthorn sites are often too wet to accomplish effective burning.
Chemical: Selective herbicide application is the
most effective control method for woody, invasive
plants. Herbicide can be applied to foliage during
the growing season, cut stems (at the time of
cutting), or the bark of the lower portions of the
stems/trunks.
Cut stem and basal bark
application can be done in the dormant season,
but is most effective when temperatures are
above freezing. Herbicides for foliar application
include Roundup, AquaNeat, Garlon 3A with
Escort, Krenite with Escort, Razor, Accord, and
Arsenal. Herbicides for cut stem or basal bark
include Garlon 4, Stalker, Pathfinder II, and
Pathway (RTU). Residual herbicides such as
Escort may be necessary to control re-sprouting,
but care should be taken if non-target plants are
in the vicinity. Only some of these herbicides are
approved for wetland habitats. Many herbicides
require a penetrating or sticking agent such as
Penevator Basal Oil or Nu-Film-P.
COMMON BUCKTHORN
Biological: Biological controls are not available for either buckthorn species at this time.
Credits and additional information:
Plant Conservation Alliance-Alien Plant Working Group
Ohio Department of Natural Resources, www.ohiodnr.gov
The Nature Conservancy, Ohio Chapter
OIPC website, www.oipc.info
Note: Maps of species’ ranges are based on records as of 2010.